Organohalosilanes are hydrolyzed to produce a wide range of polyorganosiloxanes, which are sold into many different industries. Typically, organohalosilanes are produced commercially by the Mueller-Rochow Direct Process, which comprises passing an organohalide over zero-valent silicon in the presence of a copper catalyst and various optional promoters to produce a mixture of organohalosilanes.
A typical commercial process to make zero-valent silicon comprises the carbothermic reduction of SiO2 in an electric arc furnace at extremely high temperatures. Generation of these extreme temperatures requires significant amounts of energy, which adds significant cost to the process of producing zero-valent silicon. Consequently, the use of zero-valent silicon also adds significant costs to the production of organohalosilanes.
In addition to by the Direct Process, organohalosilanes have been produced by the alkylation of tetrachlorosilane and various methylchlorosilanes by passing the vapors of these chlorosilanes together with an alkyl halide over finely divided aluminum or zinc at elevated temperatures. However, this process results in the production of a large amount of aluminum chloride or zinc chloride, which is costly to dispose of on a commercial scale.
Therefore, there is a need for a more economical process of producing organohalosilanes that avoids the need for zero-valent silicon and that does not require the costly disposal of byproducts.